Cable systems evolved initially to merely provide video to their customers' televisions. There was no upstream traffic from the customer over the cable system; instead all traffic (analog video) traveled downstream to the end users. However, as technology evolved, customers wanted to have both downstream and upstream data capability. To permit this two-way data traffic, cable operators adapted the head end of their cable networks with a “cable modem termination system” (CMTS) that communicated with a customer cable modem (CM) through the coaxial CATV cables. In this fashion, a user's PC could access the Internet though their cable modem, which received data from the corresponding CMTS. During the 1990's, the development of such data modifications for the large cable system operators (designated as multiple system operators (MSOs)) flourished. But there were competing standards such that an MSO would have to adapt to one protocol or the other to provide this data capability.
In contrast, a universal standard would lower costs for the MSOs since the equipment vendors would all have to compete head-to-head to meet this common standard. Thus, the MSOs initiated a consortium known as Data Over Cable Service Interface System (DOCSIS) that promulgated the resulting universal DOCSIS standard in the mid-1990's. A vendor that wanted to provide CMs or CMTSs would first have to get their designs certified through the DOCSIS consortium, whereupon they could sell to the MSOs or their customers. The resulting efficiency and cost savings combined with the already extensive and massive reach of the MSOs' networks made DOCSIS CMs the dominant way for U.S. users to access the Internet.
As technology has continued to evolve since the inception of DOCSIS, DOCSIS itself has evolved in turn such that various enhancements have been standardized. For example, DOCSIS 1.0 evolved to DOCSIS 1.1, then DOCSIS 2.0, and finally DOCSIS 3.0. But all these more modern flavors of DOCSIS maintain backwards compatibility with previous versions. Thus, DOCSIS has continued to dominant the market for broadband access despite the evolution of telecommunication alternatives such as DSL. Although DOSCIS has continued to evolve in this fashion, there are fundamental limits to the bandwidth that cable systems can provide. This is a problem as bandwidth demands have exploded with the development of “triple play” systems that offer video, data (Internet access), and voice (telephone) services. These bandwidth demands have been exacerbated with the mushrooming growth of high definition video content.
In contrast to conventional DOCSIS systems, optical fiber has abundant bandwidth to accommodate the modern demands for more and more bandwidth. In particular, the development of passive optical network (PON) technology offers an attractive alternative to cable with regard to meeting modern demand for bandwidth. As implied by the name, PON does not use any active means to amplify the transmissions between customer premises and the PON head end. This passive transmission keeps costs down and keeps the network relatively simple and easier to manage. These cost savings are enhanced further in a particular form of PON known as Ethernet PON (EPON) because EPON leverages the robust Ethernet (IEEE 802) standard. The EPON version of the “local loop” (the last segment in a communication network) has multiple optical network units (ONUs) at customer locations such as homes or businesses coupled by passive devices to a single optical line terminal (OLT) that may be located in the central office of an MSO. It may thus be seen that the EPON OLT is analogous to a DOCSIS CMTS whereas the ONUs are analogous to the CMs.
EPON is thus an attractive alternative for MSOs to upgrade their networks and compete with alternative PON systems offered by telecommunication competitors such as Verizon's FIOS. However, the MSOs have invested billions of dollars in their existing DOCSIS cable networks. Part of this investment includes the existing DOCSIS network managing and provisioning tools. Thus, approaches have been developed to adapt the DOCSIS protocol used by these tools to the management of EPON local loops. But these interworking approaches between DOCSIS management tools and EPON local loops have proven to be non-scalable and inefficient.
Accordingly, there is a need in the art for an efficient and scalable approach to manage EPON local loops with DOCSIS network management tools.